Improvement in sewing-machines



2 Sheets-Sheet 2-.

E. LATH BURY.

N. PETERS. Phnbmhu n mr, W-mmnn, m:

- UNITED STATES PATENT '5OFFIGE.

E. r. LATHBURY,OF BUFFALVO, NEW YORK.

IMPROVEMENT IN SEWING-MACHINES} To all whom it may concern: I

Be it known that I, E. T. LATHBURY, of

Buffalo, in the county of Erie and State of New York, have inventedcertain new and useful Improvements in Sewing-Machines; and I do herebydeclare that the following is a full, clear, and exact description ofthe same, reference being had to the accompanying drawings, making apart of this specification, in which Figure 1 is a front view of amachine with my improvements, having the table represented in section ina plane parallel with the direction of the feed motion. Fig. 2 is avertical section of the machine, taken transversely to the line ofstitching. Fig. 3 is a plan of the same with the needle-bar. anddriving-wheel removed. Fig. 4 is a vertical section in the line as w ofFig. 3, showing the'manner in which motion is transmitted to the workingparts from the main shaft. Fig. 5 is a plan of the looper and needle,illustrating their relative operations.

Similar letters of reference indicate corresponding parts in the severalfigures.

My invention consists in an improvement in the looper that operates, incombination with a needle and a single thread, to produce achain-stitch, by which the liability of the needle to miss the loops isobviated.

To enable others to make and use my invention, I will proceed todescribe its construction and operation.

A is the table or base of the machine, upon the top of which the sewingis performed.

Bis the main shaft, from which motion is transmitted to all the workingparts, said shaft working in bearings a a below the table, and receivingmotion through a small gear, 0, fast on one end, from a larger gear, D,rotating on a stud, b, secured in a standard, E, that is secured on thetop of the table A, said gear D having attached to it a crank-wheel, F,to be turned by hand.

G is the vertically-vibrating needle-arm, carrying at one end the needle0, and having its other end, which is of forked shape, hinged at d d toone end of the table A. The needlearm derives its vibrating motion topass the needle through and withdraw it from the cloth, through aconnectingrod, e, from an eccentric wrist, f, attached to the shaft B.

H is the spool carrying the thread, whichi represented in red color.

I is a well-known contrivance for producing a drag upon the thread,attached to the extremity of the needle-arm, above the needle.

h i is the looper attached to an arm, J,which is jointed by a pin, j,tothe end of a horizontally-vibrating lever, K, of the third order,working on a fulcrum-pin, k, under the table A, and deriving motion froma cam, L, on the shaft B, acting on a slide, 9, which is connected withthe said lever K, and works in a guide, Z, attached to the table. Thelooper is composed of two elastic needle-pointed fingers, attached tothe arm J at a little distance apart, one of said fingers, it, being alittle longer than the other, i, and the said fingers inclining towardeach other, so that the point of the shorter one, i, touches the longerone, h, near the point. This looper, when the needle has been protrudedthrough the cloth and retracted a little to slacken the thread on onesideof the needle to commence the formation of the loop, is

caused by the movement of the lever Kto advance and pass between theneedle and the slack thread with the shorter finger i next the needle,as shown in dotted outline in Fig.5, and as the needle is withdrawn fromthe cloth the loop is left extended on the outside of the looper, whichmoves onward so far that when the needle is withdrawn upward from theside 'of it a lateral movement of the looper will bring the open spacebetween thetwo needle pointed fingers directly under the needle with theloop extended around them, as shown in bold outline in Fig. 5, so thatthe needle, in its next passage through the cloth-the looper being inthe meantime stationary-will pass between the two fingers of thelooper,iand the loop being extended in an open condition around them,the needle cannot fail to pass through it.

It may be observed that the proper disposition of the loop is aided orpartly effected,

as in other sewing-machines making the same stitch, by the feed movementof the cloth. Af-

ter the point of the needle has passed through the loop, the looper isdrawn back out of the loop, and the elastic character of the fingers h2', which should be of tempered steel, allows their points to springapart to pass the needle when they come in contact with it.

The above-described lateral movement of the looper to throw it under theneedle is effected in the-following manner; The looperarm J worksthrough a box, M, against a screw, m, on one side and a spring, n, onthe other side, as shown in Figs. 2, 3, and 5. The side of the arm Jwhich is in contact with the screw m, is partly straight and partlyconcave, and the straight side works in contact with the screw while thelooper is passing outside of the needle, and thus allows the said armonly a longitudinal motion; but as soon as the needle is withdrawntheconcave part begins to pass the screw, and the spring is allowed to movethe arm laterally. This movement is illustrated in Fig. 5.

The needle 0 is not attached rigidly to the --needle-arm, nor to a slidewhich is rigidly confined in all directions laterally, as in othersewing-machines, but is secured in the bottom of a short bar, 1), thatis fitted into a groove, q q,

made in the T-shaped head at the extremity of the needle-arm, and issecured to the needle-arm only by a joint-pin, r, near the top. The bar19 is incapable of moving laterallyin a direction-parallel with the lineof sewing,

being confined by the sides q q of the groove, and is prevented movinglaterally so far toward the back of the groove that the point of theneedle can get on the wrong side of the looper. The latter condition isregulated by a stop-screw, s, in the back of the groove. The said bar,12, however, is capable of being swungup to ahorizontal position acrossthe line of sewing, as shown in dotted outline in Fig. 2, forconvenience of removing and replacing or changing the needle. A fiatsteel spring, 25, is screwed to the top of the needle-arm, so as topress upon the top of the bar p, and this spring holdsthe bar againstthe screw 8, when it is turned down with the needle in its operativecondition, and it also holds it steady on the pin 1' when turned up. Thespring t allows the needle to yield a little to allow the looper to passif the finger h of the latter presses hardly against it in coming out ofthe loop. The screw 8 serves to adjust the needle, so that the looperwill .work

in proper relation to it in entering the loop.

1), that is caused to give the feed motion to the cloth at the propertime by the rocking movement of the shaft P, The dog '0 is held downupon the cloth by a spring, w, attached to the arm U. W is a foot-pieceattached to the op posite end of the arm U, and so controlled by thespringw and a rocking movement of the shaft that it confines the clothto the table by a strong pressure when the dog 1) moves back afterfeeding, but that it leaves the cloth comparatively free frompressurewhen the dog '0 is giving the feed movement. I; is a handlepieceattached to the dog '0, for the purpose of applying thepressure of thehand to raise the dog 12 from the cloth to remove the latter from oradjust it in the machine. The dog 1; lifts the foot-piece W.

I do not claim the employment of a looper with two fingers or a thumband finger, as described in the patents of W. H. Johnson and L.Jennings, which fingers or thumb and finger operate differently to thefingers of my looper to produce a different stitch; but

What I claim as my invention, and desire to secure byLetters Patent, is-

The looper composed of two elastic pointed fingers, h i, and operatingin combination with the needle, so that the needle passes through thelooper while the loop is extended upon it, then escapes from it byopening its point as the looper is withdrawn from the loop,substantially as and for the purpose herein speciv fied.

WILLIAM WALKER, G. E. LATHBURY.

